JPH0993407A - Facsimile controller and facsimile communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the facsimile controller and the facsimile communication system with an excellent communication efficiency by preventing line interruption due to loss of data in the case of expanding the data into images for facsimile communication. SOLUTION: The system is provided with a means detecting a quantity of data subject to image expansion so as to select a facsimile coding compression system in response to the data quantity. When a buffer quantity of the image data is less than a threshold level on the way of data transmission, the compression system is replaced with delay compression so as to increase the communication data quantity thereby preventing line interruption. The delay compression is continued till the buffer quantity exceeds the threshold level and replaced again with the usual compression when the buffer quantity exceeds the threshold level.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a facsimile control device which develops an image of data such as characters, figures, and images created by an electronic computer, a personal computer, a word processor, etc. for facsimile communication and transmits it to a facsimile device. It relates to a facsimile communication system in which these devices are connected by a line.

[0002]

2. Description of the Related Art With the recent development of multimedia,
Not only character data but also graphic data, image data, and the like are increasing in the data handled by facsimile machines. Unlike simple character data, it takes a long processing time to convert these data into image data for facsimile communication. May become relatively long, which leads to a decrease in communication efficiency such that the data to be transmitted is not ready in time and the line is disconnected.

In a facsimile machine, it is necessary to transmit data in a procedure based on the rules established by CCITT (International Telegraph and Telephone Consultative Committee), from when a command is issued to the partner device until a response is received from the partner device. And the time from receiving the response to issuing the next command are determined.

If the data to be transmitted is not ready in time after the line is connected and a so-called timeout occurs, the line is disconnected although it is not a failure. If the line is disconnected, the connection will be reestablished. Reconnecting does not mean the same thing happens, and there are cases where efficient fast procedures cannot be used.

Most of the recent facsimile machines can use the high compression MMR system for improving the transmission efficiency, but since the facsimile coding / compression system is determined by the communication partner device, the transmission is not possible. The process cannot decide until the line is connected.

For this reason, conventionally, the image data has been dealt with by not using the MMR method of the G4 procedure or by transmitting only by the G3 procedure. As a result, the communication time of any data is long. Tended to be.

It is also known that there are two types of G3 procedures, one is for transmitting only a flag to perform delay processing, and the other is for transmitting invalid data without transmitting a flag and performing delay processing. Has been.

As a method for solving the above problems, once a line with a communication partner is secured, a method for maintaining the communication state of the line and monitoring whether image data arrives from a computer or the like within a predetermined time There have been devised a method of monitoring the image development processing time by setting a threshold value.

Among them, a technique is provided to monitor whether image data is transmitted to a facsimile machine by a timer, and if data is not created, a technique for generating a specific pattern (for example, operation of Japanese Patent Laid-Open No. 58-119037). (A timing control method) or a technique in which a fixed threshold is set for the image development processing time, dummy data is transmitted when the threshold is exceeded, or the current processing is interrupted and the line is transferred for other processing (for example, Japanese Laid-Open Patent Publication No. HEI 6). 169384 facsimile communication control method) or a technique for obtaining the amount of data that can be transmitted during data transmission and transmitting a flag to guarantee the amount of data and performing delay processing when the amount of data that has been set has not been reached (for example, a special method). Kaihei 4-196672 transmission delay processing method) is known.

[0010]

However, although the conventional method of setting the specified value of the monitoring time can monitor the approximate time, it is not accurate because it does not actually calculate the amount of data that can be transmitted. There was a problem. For example, even if the image data creation is completed immediately after the time-out is detected, dummy data will be transmitted, resulting in wasteful communication and a decrease in communication efficiency.

There is also an example in which the amount of data that can be transmitted is calculated during data transmission and delay processing is performed when the amount of data is less than a specified amount. Delay processing will be performed. It is desirable to avoid the delay process as much as possible from the viewpoint of improving communication efficiency by limiting the delay process only to the relevant page being transmitted.

In view of the above points, the present invention takes into consideration the above-mentioned point, when data such as characters, figures, and images is developed for facsimile communication, the image data creation state and transmission state are determined by the amount of data that can be actually transmitted. And a facsimile control device capable of selecting a facsimile encoding compression method according to the amount of data,
It is an object of the present invention to provide a facsimile control device capable of decompressing data transmitted by the compression method from the transmission data and expanding the data of each method, and a facsimile communication system in which these devices are connected by a line.

[0013]

The above problems can be solved by a facsimile control device configured as follows. FIG. 1 shows the principle of the present invention. A description will be given below with reference to the drawings.

The facsimile control apparatus of the present invention comprises a first method, which has a higher compression rate, of at least two facsimile encoding compression methods, and a second method, which has a lower compression rate than the first method.
And a communication control mechanism that communicates with a facsimile control device of the other party, and a first compression data storage system that stores data before compression in order to perform data compression and data communication in parallel. Storage means and second storage means for storing the transmittable data after compression; detecting means for detecting the amount of transmittable data;
Alternatively, it comprises a selection means for selecting the second method.

The first facsimile coding compression method of the compression mechanisms has a higher data compression rate than the second method and can reduce the amount of data, but the compression process takes a long time.
Usually, compression is performed by the first method having a high compression rate. In either of the first and second methods, the data stored in the first storage means in the figure is expanded into image data, compressed, and stored in the second storage means as transmission data.

When the data is stored in the second storage means, the communication control mechanism starts transmitting the compressed data to the facsimile control device of the other party. In this way, data compression and data transmission are performed in parallel. The amount of data that can be transmitted is detected by the detection means, and the amount of data is compared with a threshold value. If the amount of data exceeds the threshold value, the first method is selected. If the amount of data does not exceed the threshold value, the second method is selected.
Select the method of.

When the data compression is performed by the second method, a large amount of data can be obtained in a short time, so that the transmission data can be relatively increased and a communication delay is caused. Therefore, in order to maintain the communication state of the line. It becomes an effective means. Second
Method continues until the data amount exceeds the threshold value, and returns to the first method if the data amount exceeds the threshold value.

On the other hand, in the facsimile control apparatus of the receiving side, means for decoding from the received data which is the first method or the second method of the facsimile coding compression method, and the received data are the first and the second method. The first corresponding to the second method
And a decompression mechanism for decompressing according to the second decompression method, and decoding the compression method from the received image information to determine and execute the first or second decompression method.

Even if the compression method is changed from the first method to the second method or from the second method to the first method during the connection of the line on the receiving device side, the data is expanded according to each method. .

The facsimile communication system of the present invention is provided with the facsimile control device of the present invention as a transmitting device and a receiving device, respectively, and is connected by a line, and data is communicated by changing the facsimile encoding / compression system during the line connection.

In the communication system of the present invention, normally, highly compressed data according to the first method is transmitted / received, but when the transmittable data becomes less than a threshold value, the data is transmitted / received by changing to the second method having a low compression rate. Therefore, data delay on the line can be prevented.

[0022]

FIG. 2 shows the configuration of a facsimile control apparatus according to an embodiment of the present invention, and FIG. 3 shows the control flow thereof. In FIG. 2, reference numeral 1 is a computer such as an electronic computer, personal computer, or word processor for controlling the image conversion mechanism of the present invention, 2 is a facsimile controller for controlling facsimile communication, and 3 is a CPU for controlling the facsimile controller.

A code buffer 4 stores the data created by the computer 1, and corresponds to the first storage means in FIG. Reference numeral 5 is a decompression buffer that stores data to be superimposed on the data in the code buffer 4 for facsimile communication, and is not shown in FIG.

Reference numeral 6 denotes a compression / expansion mechanism for compressing / expanding image data based on a facsimile encoding method such as the MMR method. This compression mechanism corresponds to the compression mechanism of FIG. An image data storage buffer 7 stores the created image data and corresponds to the second storage means in FIG.

A data counter 8 of the image data storage buffer corresponds to the detecting means of FIG. 9
Is a page counter of the image data storage buffer, and corresponds to the detection means and selection means of FIG. Ten
Is a communication control mechanism for communicating with the facsimile control device of the other party, and corresponds to the communication control mechanism of FIG.

Bold arrows in FIG. 2 indicate the flow of data during facsimile data transmission in the embodiment of the present invention. A thin line arrow in FIG. 2 indicates a connection relationship between the data counter 8 and the image data storage buffer 7 of the page counter 9. In the case of facsimile data transmission, the data counter 8 is incremented by the data amount and the page counter 9 is incremented by 1 at the time of compression processing, and is decremented at the time of data transmission.

The specified value of the buffer takes into consideration the capacity of the image data storage buffer 7, the processing speed of the CPU 3, the processing speed in each coding compression, the communication speed, etc.
It is set to reduce delay processing and delay compression as much as possible. The image data storage buffer 7 has a capacity of at least two pages of total data, but can hold data over a plurality of pages when the data amount of each page is small.

FIG. 4 shows the format of the image data stored in the image data storage buffer 7. RTC (Return to Control) is a control return code,
Indicates the end of page signal.

In the present invention, the data of page 1 and page 2 is expanded and compressed for facsimile communication before the facsimile communication is started. In FIG. 3, first, decompression processing for the first page is performed. The data is created by the computer 1 and stored in the code buffer 4. Each data for the facsimile communication of the expansion buffer 5 is superposed on this data by the CPU 3.

When the processing for one page is completed, the compression / expansion mechanism 6 stores the image data in the image data storage buffer 7. Image data is compressed based on a normal facsimile coding compression method.

At this time, the format of the image data is such that image information is added to the beginning of each page and RT is added to the end of the page as shown in FIG.
Add C. The image information includes information such as compression method, pixel density, and image size. The created image data is stored in the buffer, and the data amount and page number are updated.
The data amount is added to the data counter 8 and 1 is added to the page counter 9.

When the expansion / compression process for one page is completed, it is checked whether there is a next page, and if it is the final page, a telephone call is made and the process of FIG. 3A is performed. The data is taken out from the image data storage buffer 7 and the data is sent to the facsimile by the communication control mechanism 10. The data counter 8 is decremented, the transmission is repeated until there is no more data, and the page counter 9 is decremented. When the data transmission ends, the line is disconnected and the process ends.

If there is a next page, the expansion and compression processing of the second page is performed in the same manner as the first page. If the second page is the final page, the process of FIG. Data is transmitted, and when completed, the line is disconnected and the process is completed.

If there are three or more pages of data to be transmitted, the process of FIG. 3B is activated. Here, the buffer amount of the image data that has already undergone image expansion and compression processing is shown in the page counter 9, and the facsimile coding compression method is selected according to the value of the page counter 9.

If the value of the page counter 9 is 2 or more, the normal data compression method is selected, and if it is 1 or less, the delay compression method is selected. Normally, the MMR method with high compression efficiency is adopted, and as the delay compression method, the MH method with lower compression efficiency and larger data amount than the MMR method is adopted. Delayed compression continues until the buffer amount exceeds one page, and normal compression can be restored when the buffer amount exceeds one page. The specified value of whether to perform delay compression or normal compression is determined in page units.

For the data on the third and subsequent pages, the data compression method is selected page by page up to the final page, and decompression processing is performed. Since the data transmission is performed in parallel, the data amount may change on the way page and the value of the page counter 9 may increase or decrease.
The data compression method may also change in page units. When the expansion / compression process of the final page is completed, the final page flag is set. Here, the page counter is set to -1.

After activating the process (B), a telephone call is made after waiting for the data amount in the image data storage buffer 7 to become a specified value or more. Therefore, the amount of data in the image data storage buffer 7 indicated by the data counter 8 is compared with a specified value preset in the CPU 3.

When the flag of the last page is set when the amount of data does not reach the specified amount, the process of FIG. Data is transmitted, and when completed, the line is disconnected and the process is completed. When the amount of data reaches or exceeds the specified amount, a telephone call is made. If the flag of the last page has already been set, the process of FIG.
Data is transmitted, and when completed, the line is disconnected and the process is completed.

Even if the flag of the last page is not set, if the data amount reaches the specified amount or more, the telephone call is made and then the data transmission is started. Send line data 1
Repeat page data transmission. The data counter 8 is decremented each time data is transmitted. When the data counter 8 becomes equal to or less than the specified value, delay processing by flag transmission is performed.

As is apparent from the above description, according to the facsimile control apparatus of the present invention, the data for facsimile communication of page 1 or page 2 is subjected to image decompression and compression processing before connecting the line, so that it is temporarily processed. If the line is connected to the destination, it is possible to avoid the line being cut off because the data is not in time during the communication.

Even when data is over 3 pages, data up to 2 pages is processed and data processing for pages 3 and up is started,
Since the line is connected after waiting for the data to reach the specified amount, there is no possibility that the data will not be in time.

Data is transmitted in parallel during the data processing of the third and subsequent pages, but if the buffer amount of the image data falls below the specified value in the middle, the facsimile coding method is changed to delay compression for communication. By increasing the amount of data, it is possible to prevent disconnection. This delay compression continues until the buffer amount exceeds the specified value, and when the buffer amount exceeds the specified value, normal compression can be restored.

If the buffer amount becomes less than one page or less than the specified value during data transmission of a certain page, invalid data is added as in the known example (for example, Japanese Patent Laid-Open No. 4-196672 transmission delay processing method). Also, the communication state is secured by performing delay processing.

Completion of transmission of one page means that RTC is set when data is taken out from the image data storage buffer 7.
By detecting. When the transmission of one page is completed, the page counter 9 is decremented by 1. When the page counter 9 becomes 1 during the data transmission and the remaining data amount becomes 1 page or less, invalid data is added to the transmission data to maintain the communication state.

Even if the page counter 9 is 2 or more, if the amount of data that can be transmitted falls below a specified value, a flag is transmitted to maintain the communication state. 5 pages 1 and 2
The page and the processing for three or more pages are shown. (1) of FIG.
Is 1 page, (2) is 2 pages, and (3) is 3 pages or more. In (1) and (2) of FIG. 5, the process (B) is not activated, but in (3), the process (B) is activated because there are three or more pages of data to be transmitted. After starting the process (B), the data transmission is started after the image data reaches the specified amount in the buffer.

When the page count becomes 1 after the data transmission is started, invalid data is added to the transmission data. If the amount of data in the image data buffer falls below the specified value, delay processing is performed. When the page count becomes 1 in the process (B), delay compression is selected and executed as the facsimile coding compression method for the next page.

In (1) of FIG. 6, the image data has not reached the specified amount in the buffer even after the expansion / compression process for two pages. Therefore, the expansion / compression process is further continued until the specified amount is reached before data transmission. Indicates that it is about to start. When the cumulative value of the conversion amount to the image data until the data transmission is started in (1) of FIG. 6 is D and the specified amount is K, K ≦ D.

When the image data falls below the prescribed amount in the buffer during data transmission as shown in FIG. 6B, flag transmission is performed every time line data is transmitted until the image data exceeds the prescribed amount in the buffer. In (2) of FIG. 6, since the page count is 2 or more during data transmission, there is no delay compression processing. In FIG. 6B, if the prescribed amount during data transmission is K, the conversion amount to image data at the P point is d, and the conversion amount at the Q point is D, d <K ≦ D.

In this way, the image data storage buffer 8
Has a total data capacity of at least two pages, but can hold data over a plurality of pages when the data amount of each page is small.

In (3) of FIG. 6, the image data falls below the specified amount in the buffer during data transmission and the delay processing by flag transmission is performed as in (2) of FIG. 6, but the page count becomes 1 or less. Therefore, an example in which the amount of data is increased by changing from normal compression processing to delay compression processing will be shown. At points P and Q in (3) of FIG. 6, d <K ≦ D as in (2).

In this way, the image data storage buffer 8
The data of the MMR method which is the normal compression processing and the data of the MH method which is the delay compression processing are stored in each page. In (3) of FIG. 6, the delay process by the flag transmission is performed, and since the page count is 1 or less, the delay process by the invalid data is also performed. For a partner whose flag transmission is invalid, such delay processing by invalid data transmission is effective.

In the explanation of the delay processing, the other party whose flag transmission is invalid is controlled to transmit invalid data instead of flag transmission. Delay processing such as invalid data transmission and flag transmission is an effective means for securing the communication state with the other party.

FIG. 7 shows the difference in data length between the MMR system, the MR system and the MH system coding and compressing system. Here, it is assumed that the original amount of data is the same. EOFB (End of Facsimile Block) is a facsimile block termination code and means a page end signal. When compressing data of the same length, MH method, MR method, MMR
In the method, if the data lengths are A, B, and C in this order, A>
B> C.

FIG. 8 shows a general correlation between the compression rate and the processing time in the MMR system, the MR system and the MH system coding and compression system. Generally, the higher the compression rate, the longer the processing time.

In this way, the compression method is changed from the MMR method to the MH.
By changing the method, you can increase the communication data,
Since it causes communication delay, it is an effective means for maintaining the communication status of the line.

In the embodiment of the present invention, the MMR system is adopted as the normal high compression system, and the MMR system is adopted as the delay compression system.
Although the H method is adopted, of course, other compression methods may be adopted if there is a difference between the normal method and the delay method as described above.

In the embodiment of the present invention, the facsimile coding compression method can be selected in page units. However, depending on the capacity of the image data storage buffer and the processing speed,
It is also possible to select in units of two pages or more. For example, 2
To make the page unit, it is sufficient to monitor whether the value of the page count becomes 2 or less.

If the page counter and the structure of the image data shown in FIG. 4 are changed in units of frames or lines, it is possible to select the facsimile encoding / compression system in each unit.

When it is found that the destination facsimile machine cannot support the MMR system after making a telephone call, the facsimile encoding / compression system is changed to a system which the other party can support after the line is disconnected, and the telephone call is made again. Do it again.

FIG. 9 shows a system configuration which is an embodiment of the present invention. Reference numeral 2 in FIG. 9 is a facsimile control device on the transmitting side, which is the same as 2 in FIG. Reference numeral 11 is a facsimile control device on the receiving side. 10 is a communication control mechanism, 12 is a decoding means, and 13 is a decompression mechanism. The decompression mechanism 13 has a first decompression system and a second decompression system corresponding to the facsimile encoding compression system.

The image information received by the communication control mechanism 10 is decoded by the decoding means 12, and when the expansion method is determined, the received image data is expanded by the expansion mechanism 13 in each method.

As described above, if both the transmitter and the receiver are equipped with the facsimile control device of the present invention and connected by a line, it is possible to communicate data by changing the facsimile encoding / compression method during the line connection. Become.

In the communication system of the present invention, normally, highly compressed data can be transmitted / received, and when the amount of transmittable data becomes less than the threshold value, the method is changed to a system having a low compression rate to transmit / receive data, so that the data delay on the line can be prevented and the efficiency can be improved. A good communication system can be constructed.

In the embodiments of the present invention, the facsimile control device connected to an electronic computer, a personal computer, a word processor or the like has been described as a transmission device. However, even if the data is not created by a computer or the like, image data is compressed. It goes without saying that the present invention can be applied to a general facsimile apparatus for transmitting. Further, the receiving apparatus can also be applied to a general facsimile apparatus as long as it can decode the facsimile encoding compression method and execute the corresponding expansion method.

[0065]

As is apparent from the above description, according to the present invention, if the amount of data to be transmitted to the facsimile control device of the other party is set so as not to fall below the specified value,
Normally, delay processing is not performed, high-speed communication is performed, there is exceptionally long processing time data, and even if delay processing occurs, the minimum delay processing can be automatically selected, so users are aware of delay. And a large-scale device configuration is not required, and there is a remarkable industrial effect that communication efficiency is improved.

[Brief description of drawings]

FIG. 1 is a principle diagram of the present invention.

FIG. 2 is a configuration diagram of an embodiment of the present invention.

FIG. 3 is a control flow diagram according to the embodiment of the present invention.

FIG. 4 is a format of image data transmitted in the embodiment of the present invention.

FIG. 5 is a first embodiment, a second embodiment, and a third embodiment of the present invention.
Explanatory diagram showing the process for more than one page

FIG. 6 is an explanatory diagram for explaining a process of starting data transmission after the data amount reaches a specified amount and a process when the data amount falls below the specified amount during data transmission in the embodiment of the present invention.

FIG. 7 is an explanatory diagram for explaining a difference in data length of the facsimile encoding / compression method.

FIG. 8 is an explanatory diagram showing the correlation between the compression rate and the processing time of the facsimile coding compression method.

FIG. 9 is a system configuration diagram of an embodiment of the present invention.

[Explanation of symbols]

 1 Computer 2 Facsimile control device 3 CPU of facsimile control device 4 Code buffer 5 Expansion buffer 6 Image data compression / expansion mechanism 7 Image data storage buffer 8 Image data storage buffer data counter 9 Image data storage buffer page counter 10 Communication control mechanism 11 Receiving side facsimile controller 12 Decoding means 13 Decompression mechanism

Claims (3)

[Claims] 1. A means for executing a first method having a higher compression rate among at least two facsimile encoding compression methods, and a means for executing a second method having a lower compression rate than the first method. A means for communicating with another facsimile control device, a first storage means for storing data before compression and a transmission after compression for performing data transmission in parallel with execution of the compression method. And a second storage means for storing possible data, a means for detecting the transmittable data amount, and a means for selecting the first or second method from the detection result. Compares the data amount detected by the threshold value with the threshold value, and based on the comparison result, if the selection amount exceeds the threshold value, the selection unit compares the data stored in the first storage unit with the first value. Select the method execution method, If the value does not exceed the threshold value, the second method executing means is selected until the value exceeds the threshold value, and the data compressed by the selected first or second method executing means is transmitted by the communication means. Facsimile control device. 2. The received data is compressed by a first method having a higher compression rate of at least two facsimile coding compression methods or a second method having a lower compression rate than the first method. And a means for decompressing the data by the first and second decompression methods corresponding to the first and second methods, and the first or second data from the data. A facsimile control apparatus characterized by determining and executing the expansion method. 3. A transmitting device, which executes a first method having a higher compression rate of at least two facsimile coding compression methods, and a second method having a lower compression rate than the first method. And means for communicating with another facsimile control device, and first storage means for storing uncompressed data in order to perform data transmission in parallel with the execution of the compression method. A second storage means for storing the transmittable data after compression, a means for detecting the transmittable data amount, and a means for selecting the first or second method from the detection result are provided. , Comparing the data amount detected by the detection unit with a threshold value, and based on the comparison result, the selection unit, if the data amount exceeds the threshold value, for the data stored in the first storage unit, The first method execution means If the data amount does not exceed the threshold value, the second method execution means is selected until it exceeds the threshold value, and the data compressed by the selected first or second method execution means is transmitted by the communication means. And a means for decoding from the data whether the received data has been compressed by the first method or the second method of the facsimile encoding compression methods as a receiving device, Facsimile control including means for decompressing the data by first and second decompression methods corresponding to the first and second methods, and determining and executing the first or second decompression method from the data A facsimile communication system comprising a device and communicating data by changing a facsimile encoding compression method during line connection.